1. Field of the Invention
The present invention relates generally to a semiconductor device which includes a graphene layer, and more particularly, to a semiconductor device which includes a graphene layer, and first and second plural contacts.
2. Description of the Related Art
Owing to reports of graphene's extremely high intrinsic mobility and unique electronic structure along with demonstrations of device cutoff frequencies in the hundreds-of-gigahertz range, graphene transistors have become of great interest for electronic applications.
FIG. 1 illustrates a related art graphene device (e.g., a graphene transistor and, more particularly, a graphene field effect transistor (FET)) 110.
As illustrated in FIG. 1, the graphene device 110 may include a transistor having a front-gate configuration and including a graphene channel 116 formed on a substrate 105 (e.g., formed on an upper surface of the substrate 105) such as an SiC substrate, a gate dielectric 114 formed on the graphene channel 116 (e.g., formed on an upper surface of the graphene channel 116), source and drain electrodes 118a, 118b formed on the substrate 105 and contacting the graphene channel 116 and the gate dielectric 114 (e.g., contacting a side surface of the graphene channel 116 and a side surface of the gate dielectric 114), and a gate 112 formed on the gate dielectric 114 (e.g., formed on an upper surface of the gate dielectric 114).
In particular, the source and drain electrodes 118a, 118b may include metal contacts which are formed on a surface of a layer of graphene which forms the graphene channel 116.
As the performance of graphene devices has continued to increase, so also has the understanding of transport properties and performance limitations. It has become apparent that controlling the interface between the layer of graphene, and the metal contacts (e.g., the source and drain electrodes 118a, 118b) (i.e., controlling the metal-graphene contact interface) is one of the foremost challenges to maximizing performance in the graphene device 110. A variety of factors, such as metal-induced doping of the graphene in the graphene channel 116, may result in contact resistances that can often dominate the operation of the graphene device 110 (e.g., graphene transistors).
To reduce the contact resistance, various metals have been studied for the metal contacts. In addition, a variety of contact annealing conditions have also been studied.
However, to date, none of the related art approaches has provided a complete solution to meaningfully reducing (e.g., completely minimizing) the role of contact resistance in the performance of the graphene device 110.